期刊
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
卷 -, 期 7, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/1475-7516/2017/07/022
关键词
cosmological perturbation theory; physics of the early universe; cosmology of theories beyond the SM
资金
- Discovery Grant from Natural Science and Engineering Research Council of Canada
- Perimeter Institute
- Government of Canada through the Department of Innovation, Science and Economic Development Canada
- Province of Ontario through the Ministry of Research, Innovation and Science
This paper presents the first derivation of the quadratic action for curvature perturbations, ?, within the framework of cuscuton gravity. We study the scalar cosmological perturbations sourced by a canonical single scalar field in the presence of cuscuton field. We identify ? as comoving curvature with respect to the source field and we show that it retains its conservation characteristic on super horizon scales. The result provides an explicit proof that cuscuton modification of gravity around Friedmann-Lemaitre-Robertson-Walker (FLRW) metric is ghost free. We also investigate the potential development of other instabilities in cuscuton models. We find that in a large class of these models, there is no generic instability problem. However, depending on the details of slow-roll parameters, specific models may display gradient instabilities.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据